Determination of the coefficient of thermal expansion of high performance concrete from initial setting

Title: Determination of the coefficient of thermal expansion of high performance concrete from initial setting
Author(s): H. Kada, M. Lachemi, N. Petrov, O. Bonneau, P.-C. Aïtcin
Paper category : journal
Serial title: Materials and Structures
Abreviated Serial title: Mater. Struct.
ISSN: 1359-5997
Publisher: RILEM Publications SARL
Volume: 35
Issue: 245
Issue date: 2002-01-01
Publication year: 2002
Pages: 35 - 41
Total Pages: 7
Nb references: 16
Language: English

Abstract: Autogenous shrinkage,which is a consequence of the absolute volume contraction resulting from cement hydration,occurs in any concrete but its effect is particularly amplified in high performance concrete in which it can be as large as drying shrinkage.
Autogenous shrinkage can be directly measured in concrete samples under isothermal conditions but from a practical standpoint the experimental procedure is not always possible.
On the other hand,it can be valuated after having taken into account volumetric variations due to the release in heat during cement hydration.
To separate the thermal effect from autogenous shrinkage,it is necessary to know at any moment the evolution of the coefficient of thermal expansion of the concrete from initial setting.
A simple method to determine the coefficient of thermal expansion at early ages is proposed in this paper.
It consists in submitting concrete samples instrumented with vibrating wire extensometers to thermal shocks.
The response of the concrete sample to this shock results in a nearly instantaneous deformation,which is measured by the sensor.
These deformations,as well as the temperature signal,are used to calculate the coefficient of thermal expansion.
By repeating this experiment at various ages,it is possible to follow the variation in the coefficient of thermal expansion of the concrete over time.

Online publication: 2001-11-27
Classification: Scientific Reports
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/13684